Comparability of Railway Rail Steels Low Cycle Fatigue Behaviour

Several different kinds of steel are used for railway rails. From simple pearlitic steels for rarely used tracks over premium pearlitic steels for high performance lines to special bainitic, martensitic and austenitic steels for switches and crossings. Most of these steels have been trial and error developed over time in track. The main reasons for replacement of rails are fatigue and wear. For material selection purposes fatigue properties must be taken into account. Simple fatigue testing methods that allow comparison of different steels are scarce in literature.In this thesis results from low cycle fatigue test of four different steels are compiled and a comparison based on strain energy density is presented. The steels are all used for railway rail application. One is near fully pearlitic steel which is mainly employed in common track. The other three are used for different parts in switches and crossings. It is one carbide free bainitic steel, one high manganese austenitic steel and a martensitic steel. Results show the martensitic and bainitic steel as the superior steels at low strain ranges